A Study of Cognitive Radio Sensing Techniques for Optimum Spectrum Utilization

Background: The spectrum scarcity plays a vital role in wireless communications. We are in the situation to use it through an efficient methodology. Objective: To identify the holes in the spectrum through an efficient spectrum sensing technique and to allocate the bands to the unlicensed users (Secondary Users - SU). Methods: It has been proposed to make a comparative study among the existing spectrum sensing methods based on the following parameters such as Probability detection (Pd) measurement, Algorithm, Decision fusion method, Network model. Results: A comparative study has been made to find the pros and cons of the existing techniques with their limitations and the field of application. Cooperative Spectrum Sensing (CSS) technique significantly consumes less energy and takes less time to report to Fusion Centre (FC), since it utilizes Log Likelihood Ratio (LLR) Method to find the probability of detection using Chair-Varshney rule in local sensing with parallel report approach in the cluster based network. Conclusion: Through the study and the comparison of parameters in literature, it is found that CSS provides better detection. Therefore, this technique can be considered as an efficient technique to find the holes and to share the frequency with SUs.